In the latest edition of the Scientific American Mind, there are two (and more) interesting articles:

How the brain creates reality - what we see or think we see;

and another on the phenomenon of phantom pain - Spinal Cord Repair - and when the attempt to regenerate nerves is done too early, the dendrites can form wrong connections, and phantom pain can result. Interesting, the brain recognises the fact that the failure of nerve endings searching for appropriate docking areas ends up as an interpretation of 'missing body bits'....